400 LABORATORY MANUAL OF HUMAN ANATOMY 



Intercostal Nerves (Nn. intercostales). (Vide Fig. 198.) 



The intercostal nerves should now be studied. Each nerve 

 runs on the internal surface of a rib near the lower margin in 

 the sulcus costae, along with the V. and A. intercostalis. The 

 nerve may be brought into view by pulling downward upon the 

 ramus cutaneus lateralis. Follow two or three of the nerves 

 from their origin to their termination. Note that the Nn. inter- 



FIG. 198. 



Nervus spinalis (thoracalis) Rarmis cutaneus dorsalis (medialis) 



Ramus cutaneus dorsalis (lateralis) 



calis (nervus intercostalis) 

 -V -,Rami musculares 



Medulla spinalis 



Radix anterior 



Ramus communicans 



Ganglion trunci sympathici iu 

 cross-section 



-Ramus posterior 

 of the ramus cuta- 

 neus lateralis 



,Ramus cutaneus 

 lateralis 



Ramus anterior of the 



ramus cutaneus 



lateralis 



<r- 



Ramus cutaneus anterior with a medial and 

 a lateral branch 



The course and branching of a thoracic nerve, nervus thoradcus, in a segment of the body. 

 Schematic. (After Toldt, Anat. Atlas, Wien, 1903, 3 Aufl., p. 810, Fig. 1240.) 



costales are really the anterior rami (rami anteriores) of the 

 thoracic nerves (Nn. thoracales). Study the following branches : 



(a) Muscular rami (rami musculares). 



(b) Lateral cutaneous ramus (ramus cutaneus lateralis [pectoralis et 



abdominalis]). 



(c) Anterior cutaneous ramus (ramus cutaneus anterior [pectoralis et 



abdominalis]). 



